I’ve used Mac’s and PCs. I like Mac’s but I like being able to customize and personalize my PC, and it’s easier for me to do that on Windows. My linux system is another story… 
I use Firefox and IE 7. I used to use Opera, but for some reason, I just stopped using it.
I used Firefox because it has AdBlock. AdBlock FTMFW
I’ve used mac in the 3D animation industry… utter crap, I had more crases, lock ups, skipped frames in 3 months then in 2 years on a PC or SGI IRIX based system… support on both Apples side and the many SW companies was ruinously slow… never again did a MAC infiltrate any of my work spaces… keep em for the AVID. fine. back then… but now forget it. MAC"s really are a very very specific niche market… Like those guys who makes windsurfers for trans oceanic crossings… Niche markets…
Autocad has almost no place in the modern work place, with 3D systems coming online that will do very good 2D outputs their is no need. Autocad is the ultimate bloatware… 7-10 key strokes sometimes to get to one function. common. In the Eng. world the only people I know that use Autocad anymore are the home users, who use it, becuse they learned it YEARS ago and can think in it pretty quickly… However we’ve converted the Aircraft shop to Rhino and solidworks. with ramsgold and Visualmill on our CNC systems… this also allows us to interface with anyone else.
bah MAC’s have swapped places with the PC… it used to be the ‘PC was the spreadsheet machine’ and that was it… now the MAC is the ‘home movie makers machine’… and thats about it.
Trust me, Autocad is bloatware… but as far as my work is concerned, it’s the only program I can use. We are pretty much required to use DWG format for everything, 2D and 3D. I tried Solidworks, Pro/E, Solid Edge and a few other, but they are all designed for part/machine desing, not building/site layouts… Also 99% of them time we must submit a DWG file, and there are no exceptions.
We have Acad2000, 2005, 2007 at work and we end up using 2000 and 2007 most of the time.
If you have any idea what program we can use for building and site layouts (2D and 3D) and that can convert the drawings in 100% accurate DWG files, just tell me 
I’ve seen program that can convert to DWG file format, but if you look closely, they do miss something during that process… i.e. the decimal points are off by like 0.001 or something weird like that… so it’s not 6000mm but 5999.999 or 6000.001 get it? So that’s why we use autocad for DWG files…